Remote Services Concept

Class cds.RemoteService is a service proxy class to consume remote services via different protocols, like OData or plain REST.

• cds.RemoteService class
  • class cds.RemoteService extends cds.Service
• cds.RemoteService — Configuration
  • HTTP Client
  • CSRF-Token Handling
  • Timeout Handling
• More to Come

cds.RemoteService class

class cds.RemoteService extends cds.Service

cds.RemoteService — Configuration

The cds.RemoteService configuration allows you to define various options for connecting to remote services.

HTTP Client

CAP supports two HTTP clients for outgoing remote service calls: SAP Cloud SDK and CAP's built-in native fetch client.

SAP Cloud SDK

If the SAP Cloud SDK HTTP client (@sap-cloud-sdk/http-client) is installed, CAP uses it by default. The client provides full support for all SAP BTP Destination service features including on-premise connectivity.

Learn more about SAP Cloud SDK.

Native Fetch Client Beta

CAP provides a built-in remote client that uses the native Node.js fetch API, including support for resolving named destinations from the SAP BTP Destination service.

Current limitations

The native fetch client supports only proxy type Internet and authentication types NoAuthentication, BasicAuthentication, and OAuth2ClientCredentials. Other authentication types are resolved on a best-effort basis via the native destination client.

You don't need SAP Cloud SDK for local development. For production, the SAP Cloud SDK is only required if you use authentication types or proxy configurations not yet supported by the native client.

The client selection follows this priority:

1. Explicit configuration - set cds.remote.native_fetch to true or false, CAP uses that setting.
2. Default behavior - CAP uses native fetch when you haven't installed @sap-cloud-sdk/http-client.

Learn more about SAP BTP Destination service support for the native fetch client.

CSRF-Token Handling

If the remote system you want to consume requires it, you can enable the new CSRF-token handling of @sap-cloud-sdk/core via configuration options csrf and csrfInBatch. These options allow to configure CSRF-token handling for each remote service separately.

Basic Configuration

"cds": {
    "requires": {
        "API_BUSINESS_PARTNER": {
            "kind": "odata",
            "model": "srv/external/API_BUSINESS_PARTNER",
            "csrf": true,
            "csrfInBatch": true
        }
    }
}

In this example, CSRF handling is enabled for the API_BUSINESS_PARTNER service, for regular requests (csrf: true) and requests made within batch operations (csrfInBatch: true).

Advanced Configuration

Actually csrf: true is a convenient preset. If needed, you can further customize the CSRF-token handling with additional parameters:

"cds": {
    "requires": {
        "API_BUSINESS_PARTNER": {
            ...
            "csrf": {  
              "method": "get",  
              "url": "..."
            }
        }
    }
}

Here, the CSRF-token handling is customized at a more granular level:

• method: The HTTP method for fetching the CSRF token. The default is head.
• url: The URL for fetching the CSRF token. The default is the resource path without parameters.

Timeout Handling

The requestTimeout setting in the cds.RemoteService configuration specifies the maximum duration, in milliseconds (default: 60000), to wait for a response from the remote service before timing out.

Configuration Option

{
  "API_BUSINESS_PARTNER": {
    "kind": "odata",
    "credentials": {
      ...
      "requestTimeout": 1000000
    }
  }
}

Tip

See Using Destinations for more details on destination configuration.

More to Come

This documentation is not complete yet, or the APIs are not released for general availability. There's more to come in this place in upcoming releases.